Tractor-chain



C.'L.BEST.

TRACTOR CHAIN.

APILICATION FILED FEB. 15 i917.

1 ,356,958, v Patented Oct. 26; 1920.

, C. L. BEST.

` TRACTOR CHAIN.

APPLICATION FILED 4HEB. l5 1917.

y s SHEETS-Smm 2.

my g mm l anwvwoz.

'Patented oct. 26,1920.; 1

C.| BEST.

TRACTOR CHAIN.

APPLICATION FILED FEB.15,1917.

1,356,958. Patented oet. 26,1920.

3 SHEETS-SHEET 3.

UNITED STATES PATENT oFFicE.

CLARENCE LEO EEsT, OE OAKLAND, CALIFORNIA, AssIGNOR- To THE HOLT MANU- FACTURING COMPANY, or sTOcxToN, CALIFORNIA, A CORPORATION OF CALI- FORNIA; l f.

Specification of Letters Patent.

TRACTOR-CHAIN.

Patented oet.` 2o, '1920.

. original appuc'tion med Apri; e, 1914, -seriai No. a 29,84s. A inviami and tins application med February 1 :15,- 19,17.V Serial No. 148,776.

r citizen of the United States, residing lat 4 To all whom t may concern;

Be it known that I, CnAiiiii-ioi-iLEo BEST,

Oakland, in thecounty vof Alameda and l State of California, have invented certain new and useful Improvements in Tractor- Chains, of `which vthe following is a1 specification, reference being had therein to the accompanying drawing.

The present invention yrelates t-improvements in tractor chains.

The object of the invention is to provide an improved tractor chain for self propelled tractor engines in which excessive friction and Wear on the hingcpins will be greatly reduced, and that'will be very durable'and efficient in use.

An important object of theinvention also is to provide an improved track laying tractor chain comprising connecting means y for the chain link members constructed and arranged to provide a line contact rocking bearing between portions of the connecting means when the chain is fiexed, and a rela tively broad surface contact bearing be` tween portions ofthe connecting means when the links extend in longitudinal alinement in the active or traction fold of the chain.

Another object ofthe invention is to provide an improved track laying tractor chain of the character referred to of simple con-V struction that can be cheaply manufactured.

`The invention, with other objects and advantages thereof, and the 'particular conf struction, combination and arrangement of parts comprising the same will be understood from the following detailed description when considered with the accompanying'drawings forming part hereof and illus'v tratincr one embodiment of the invention.

In the drawings,

-V Figure 1 is a side elevation of part of a Fig. 4 is a tractor engine equipped with an improved tractor .chain constructed in accordance with the present Invention;

Fig. 2 is a top plan View, on an"enlarged scale, of a portion of the traction fold' -f Fig. 5 is. a transversesection of the construction illustrated in Fig. 4.

Fig. Gis a detail perspectiveview of one of the bearing members -of the chain, and

Fig. 7 is a detail perspective view, of an- -fotherl of the bearing members of the chain.

I have illustrated in the drawings a preferred embodiment ofthe invention,- the construction shown being fully set forth and `described in `my application, Serial No. 829,848, iled April 6, 1914, the ypresent application being a division of said A former case; V.In the dr'awing,"`a` designates a tractor truck frame having at one end a driving' *and supporting sprocket Wheel b, and at its other end an idler' wheel c. Extending around and engaging the sprocketivheel I) and idler wheel c is the endless traction chain d.

The chain d is made up of link' members each comprising side plates-ffl d2 connected by'bolt d3 and also by tread `plates d4 witli their holding boltsd5.

plates d. d2 is provided atone eiid'a ful- 'Between thev side cru'm casedG rigidly secured at each of its ends to the side members by any suitable means. vInteriorly of the fulcrum case d is' provided a longitudinallyv extending radially projecting rib or fulcrum Z7 extending to the axis of-the case d6. The iiiner, surfaceof the rib or fulcrum o" is beveled radially'from the plane of its longitudinal center on oppositesidesof itscentral plane thus forming the outer` end ofthis fulcrum into' an obtuse angle, the apex of which is the axis `of the case do. Between the side plates d d2 at the opposite end of the case df; is `provided a strutf.s of less diameter than the interior' diameter of the case Il and having a flat working surface (Z9 forniing a plane extending longitudinally of the j. strut (Z8 along its axis to rock or see-saw onthe louter end of the fulcrum' dl. This strut ds is rigidly secured at each` of its ends tfo the side members 77 d2 with its-Working plane Z9 set at an angle with the longiico tudinal horizontal plane of the hinge axis of 1 f `the said members. This angle corresponds to one of the angular surfacesdl" of the `fulcrum Z7 of the case d6 to lie flat against;

the same, as indicated in Fig. 3 of the draw-l ings, when the links of the chain extend in longitudinal alinement in the active or traction fold ofthe chain, and to rock or oscillate upon the outer end or apex of the fulbers haveaa corresponding oset, so that the links consisting of the two side members d d2 may be assembled into a parallel sided continuous chain hinged together by each strut ds passing through its coacting fulcrpum case.

The tread plates d* ofthe links and chainl thus described extend somewhat beyond the hinged axis of the links of adjacent treads being suitably yconiforinedrto each other to overla It will be observed that the particular tractor chain construction hereinbefore de-4 scribed provides for a line contact rocking bearing between portions -of the link con necting means 'when the links are flexed so.

that all of the advantages of the line contact bearing, such as greater flexibility with less s friction and wear, and avoidance or need` of lubrication, etc., are obtained, at the same time when the links extend in longitudinal alinement in activeposition in the traction fold of the chain, a relatively broad flat bearing between portions of the connecting means is provided which serves to give increased support to and to afford a firmer and more effective traction tread.

It will also be noted that the connecting means for the link members of the chain is very simple in construction and can be cheaply manufactured.

Intermediate oi'the` driving and support-v ing sprocket wheel b and idler Wheel c is an anti-friction chain guide e rigidly secured to the truck frame a, the guide being positioned between the truck frame and the lower or traction fold of the chain.

The anti-friction chain guide is shown as comprising oppositely disposed members or plates e', each of which has associated therewith a plate e2. The plates e and e2 are complementarily formed to provide ball racesl c5 for anti-friction balls c, the plates e2 being held in position against the plates e by transverse fastening members e4. As

will be understood the balls c* of the races are adapted to engage the chain at opposite sides thereof serving as lateral and vertical abutments and guides as illustrated in Fig. 5 of the drawings. v i

vI desire'it to be understood that variations and minor changes in the particular construction illustrated in the drawings, as will appeal Ito those skilled in the art, may be made without departing from the broad principles of the invention.

Having thus described the invention, wha

I claim is:

A self-laying track for' vehicles, comprising articulated link sections, each section' l being made up of parallel side plates, having their inner longitudinal ed es formed with rails to support a truck mec anism and carrying at their outer longitudinal edges a tread plate, a gudgeon block connecting the side plates together at one end and forming a pin tooth for engagement with a sprocket wheel, the oppositeends of said side plates gudgeon block.whereby Awhen the link sections are-in a straight line the flat sloping side of: the rib sea-ts` against the pin and when the link sections are angularly disposed as in passing around the sprocket i wheel, the ridge of the rib only contacts with the'pin.

In' testimony whereof I hereuntol aiix my signature in the presence of two witnesses.

CLARENCE LEO BEST.

Witnesses:

E. H. WHEELER, H. C. MONTGOMERY. 

